16” 308 Heavy or Light bullet?

[bmicek]

I’ve thumbed through countless pages doing a search on this and really haven’t come up with an answer so I’m looking for input. I know trial and error is the best way to get my answer but in the meantime I’m asking you guys for your experience.

I just got a DTA SRS A2 with a 16” 1:8 308 barrel. It’s a 16” barrel so right out the gate I’m aware my performance is limited. But I’m trying to make the best of it. I’m stuck between using a 155gr bullet like a Scenar/ELD-M/SMK/etc versus something like a 168/178 ELD-M (or others like a 175SMK). My twist rate says shoot something heavier. But in some threads, guys preach lighter bullets in a shorter barrel rifle so you can wrench out more velocity. Some threads also say the opposite and say you need to shoot 2800-2900+ FPS to get the benefit of a 155gr.

My intended use is general target shooting in the 550-800 yard range with the occasional 1000yd shots for fun. Like I said, I’m well aware my setup is not optimal for 1000yd shooting and I would bet 1000yds will account for 10% of my time spent shooting. The more I research this, the more I think I should just get some 168 eld-m’s and roll with it. Good BC and fair velocity, just a good middle of the road bullet.

 

[Dogtown]

I went down that route about 12 years ago when I got the same 16" conversion for my SRS. Turns out shooting 175SMKs at 2500 is still really effective out to 1000 yards. The twist rate on that barrel is fast because it was originally designed for subsonic loads, but it works great at distance too. In fact, I won a 250-800 yard stage of a match with that little guy in NZ way back then.

Edit: load uses 45gr Varget @ 2.800" Right on the edge of pressure, but solid.

 

[bmicek]

I went down that route about 12 years ago when I got the same 16" conversion for my SRS. Turns out shooting 175SMKs at 2500 is still really effective out to 1000 yards. The twist rate on that barrel is fast because it was originally designed for subsonic loads, but it works great at distance too. In fact, I won a 250-800 yard stage of a match with that little guy in NZ way back then.

Edit: load uses 45gr Varget @ 2.800" Right on the edge of pressure, but solid.

Good info, I probably am attempting to make it more complicated than it needs to be. Sounds like a good plug for the 175smk

 

[straightshooter1]

Good info, I probably am attempting to make it more complicated than it needs to be. Sounds like a good plug for the 175smk

175 SMK's are indeed good. But you should seriously consider Sierra's new 169 SMK for the longer distances (I give them an edge over the 175's). And for the shorter distances 168 SMK's are still outstanding. The way the market is these days, it's good to have more than one available that can perform well.

 

[M4orturnate]

The 169s are awesome out of my 20" ar10. The 155 palmas(2156) are also a damn good bullet but at 2720fps the get their ass kicked in the wind

 

[Heffo]

Will have no dramas and lots of fun with that shooting out to 800. My favourite load is 175 Berger OTM with 44.8g Varget @ 2590fps. The heavies do better than 155s, you don’t gain much velocity, but both will work. Cheers.

 

[db2000]

I get 2500 fps w/ 43 Varget and 185 Jugg and 2630 fps w/ 168 SMK and 42.5 H4895.
The ballistics are way better at 800 with the Juggs. 18” barrel though.

 

[three horsemen]

With a 1:8 twist I would definitely go with the 175gr+ bullets. The heavier bullets will be slower out of the muzzle but will loose velocity slower than the lighter bullets and will have more power when they reach the target. Also the wind will have less affect on the higher BC heavy bullets. It's a no brainer IMO. Your lucky you got the faster twist barrel for what you have. That's why the 200+ grain 300BLK bullets are so effective. But you can also shoot longer range with your set up too. Win, win.

 

[bmicek]

I ended up ordering a couple hundred 169SMK’s with plans to move up to something like a 185 Jug if I don’t get the results I want.

 

[straightshooter1]

I ended up ordering a couple hundred 169SMK’s with plans to move up to something like a 185 Jug if I don’t get the results I want.

Let us know how they do for you . . . preferably in some detail. Good Luck.

 

[reewik]

Mine is a 16.25" 308 and the 175's are superb for me. I am also experimenting with 190's. I have not yet had a chance But I have em so why not try em.

 

[FCS]

190 SMK does really well from 16” bbl in SAAMI chamber.
Same burn rate powder as needed w/175-168 gr bullets but use less.
Lose less performance when paired w/shorter bbl.
190 SMK is about 7% higher BC, only about 2% slower than 175 SMK. Net gain of about 5%.

I cannot deny, I like big bullets.

 

[bmicek]

190 SMK does really well from 16” bbl in SAAMI chamber.
Same burn rate powder as needed w/175-168 gr bullets but use less.
Lose less performance when paired w/shorter bbl.
190 SMK is about 7% higher BC, only about 2% slower than 175 SMK. Net gain of about 5%.

I cannot deny, I like big bullets.

The 169SMK is intriguing. I’d be curious to see how it stacks up to the 190SMK where you are comparing BC and velocity. Faster than the 175SMK and better BC. FYI I saw midway had factory seconds 190gr bullets that look like SMK’s if you were looking for more.